Combined steam and hot-air engine



D. MUSSBLMAN.

.AIR ENGINE.

N0.-y 32,200. Paigen'tedApr. 30, 1861.

jay/OL r Ar" UNITED sTaTEs PATENT orrrce.,

DARIUS MUSSELMAN, OF GHARITON, IOWA.

COMBINED STEAM AND HOT-AIR ENGINE.

Specification of Letters Patent No. 32,200, dated April 30, 1861.

To all 'whom it may concern: i

Be it known that I, DaRrUs MUssnLMAN, of Chariton, in the county of Lucas and State of Iowa, have discovered a new and useful Mode of Generating and Combining Hot Air, Steam, and the Gaseous Products of Burning Fuel as a Motive Power for Propelling Machinery; and I do hereby declare that the following is a full, clear, and exact description of the construction of the same, reference being had to the annexed drawings, making a part of this specification.

In the drawing Figure l, A, is the furnace chamber, which with furnace B, and other parts interior to chamber A, is shown by dotted lines. Chamber C, shown by full lines, is a strong airtight chamber completely surrounding chamber A, with a cold air space between them, for the passage of the cold air from the air pump'D, to the furnace B. The arrows in the air space show the direction of the air in its course from air pump D, to furnace B. The pipe E, conducts the heated air and gases from the furnace to the space F, beneath and surrounding the lower part'of the steam generator G, which last is extended through chambers C, and A', its lower part being contained in the latter chamber. H, is a pipe within the steam generator, through which the hot air and gases pass from space F, into the steam generator g. y

K, is a stack of circular perforated plates, iitted to the interior of the steam generator, and arranged in a frame about a half an inch a aart.

1L, is a pipe pierced with a great number of small holes, located inside of generator G, and extending to the bottomof the latter in contact with its side, through which pipe the water from the force pump enters the generator, sprinkling the adjacent plates and the lower part of said generator.

W, is a pipe connecting the steam gener ator to the engine.

N, is a plunger tapered at its lower 'extremity, working air tight in the short tube O, by means of metallic packing fixed in said tube. The upper end of plunger N, is attached to lever a, which is made adjust able by means of notched post Z), against which said lever is pressed by spring rod o', the other end of lever a, is attached to spring (Z, a pointer is fixed to the latter to indicate on scale o, the pressure in pounds to the square inch on plunger N. The scale post e, with the rod f, serves also as a support to lever a, and plunger N. The arm g, attached to the plunger N, rises and falls with the latter, giving motion to rod L, which passes through stuffing box k, and is attached to sliding valve Z, which last isrrinserted in pipe P, which extends down into:`

space F. The aperture m, in pipe P, opens into the cold air space between chambers A, and C. The aperture n, opens into the hot air space F.

The design of plunger N, and the devices connected with it, is to prevent the production of a greater .amount of motive power than is required to propel the-engine at -the proper force and speed. Thus, when the hot air entering the generator tends to produce more than the required amount of m0- tive power; the increased pressure acting on plunger N, causes the latter to rise, by which valve Z, is raised so as to partly close aperture m, and at the same time leave a, partly open; which shuts oil' a portion of the air flowing from the air pump to the tire, and turns it into space F, where it mixes with the overheated 'air entering the steam generator from the furnace, which mixing, instantly checks the tendency to produce surplus power. Wvhen a high pressure is desired, lever a, is brought down to one of the lowery notches in post o, which at the same time lowers plunger N, and sliding valve Z, so as torequire a great increase of pressure to raise valve Z, suficiently high to turn a portion of cold air into hot air space F. For a low pressure, lever a, is placed in one of the upper notches in post b. In case of a great and sudden expansion of steam &c. in the generator, plunger N, will rise sufficiently high to allow the surplus power to escape,the taper ofV the plunger, at its lower extremity, when opposite the packing ring,r allowing said escape, without said plunger rising entirely above the packing ring. This device, in connection with those for modifying the heat of the air in space F,

. will eectually prevent explosions.

The float o, in the steam generator., (Fig. 2,) attached to rod 79, actuates valve o, in tube 1^, through which last the water flows to the force pump, preparatory to its admission into the steam generator. Vhen the water in the` generator is at the proper height', the valve g, shuts off a portion of water from the pump equal to the excess of that required in the generator. The float 0,

is pointed at its lower extremity giving this' Y of spray. Y

The fuel feeder g', contains two valves s, and t, formed of plates of metal arched to give greater strength. Each valve has a small opening near the points where they are hinged, which are closed airtight by rods u, and fu, which slide beneath valves s and t. The valve t, has attached to its upper side a protecting plate, to prevent injury to said .valve when feeding fuel to the furnace. The

door w, beneath .valve t, opens into the furnace. Lever actuates the rods u, and o, for opening and closing valves s, and z5. In feeding fuel to the furnace, lever is moved so as to withdraw rod u, from beneath valve s, when the escape of condensed air that may be between the valves s, and t, through the opening in valve s, allows the latter to fall. Fuel is then placed in the fuel feeder, resting on the protecting plate attached 'to valve t, lever x, is then moved so as to push rod u, against valves, raising the latter to its place. By pushing rod u, somewhat farther beneath valve s, valve t, is allowed to fall, by the withdrawal of rod fu, from beneath the latter valve,-dropping the fuel upon door w, which opens by the weight of said fuel, which falls thence into the furnace. Door lL0, rises to its place by means of weights or springs attached to it for that purpose. Door fw, may be composed of two shutters. Lever m, keeps both valves closed, but will not-allow but one to be open at the same time. As a general rule, both valves should be kept closed during the intervals of supplying fuel to the furnace.

It is evident that` some means must be provided to prevent soot and ashes from being carried linto the hot air space F, and thence into the steam generator G. This is accomplished by the peculiar form and arrangement of pipe E, which conducts the hot air from the furnace B, to the hot air space F. The side of pipe E, next the furnace, and the bottom of said pipe next the ash pan, R, has a slit or seam in its whole length lcommunicating with ash pan B. A device similar to the twist of an auger is fitted into pipe E, extending the whole length of the latter. The furnace B, and ash pan R, are separated from the hot air space F, by a partition S, crossing furnace chamber A, vertically between the furnace tween the latter and ash pan B. Partition S rests against that side of pipe E, next the furnace, and the lower part of said pipe next the ash pan R. Both the vertical and horizontal parts of this partition, have a slit or seam coinciding with that in pipe E. Thus, the hot air from the furnace, in passing toward space F, acquires while passing through pipe E, a whirling motio-n, by means of the twisting form of the device containedV in saidpipe. This whirling motion causes the soot and ashes that may be borne along with the hot air, to tend outward from the center of pipe E, by which it is thrown through the seam or slit in said pipe, falling thence into ash pan R. A portion ofthe hot air also passes through the seam in pipe E, with the soot and ashes, and renters the furnace through the grate be` neath the lire, by which it is reheated and passes into pipe E, as before. This return of a portion of the hot air to the furnace, being continual, gives a higher temperature to the whole body of hot air passing into space F, and generator G. Fig. 3, gives an end view of pipe E, showing its connection with partition S.

The combined operation of all the parts embodied in the preceding descriptions, remains to be described. The engine, to which my invention is applied, should have a cylinder of three or four times the capacity of the air pump D, or two thirds that of the steam generator G. The air pump D, is worked stroke for stroke with the engine. Preparatory to starting the engine, the force pump and air pump are disconnected from the engine gearing. Air pump D, is then worked by a lever, which forces condensed air into chamber C, which with its interior parts, including generator G, now forms a reservoir of condensed air for starting the engine. The force pump is then worked by hand, by which a small quantity of water is forced into the generator, sprinkling the plates K, and covering the bottom of the generator a few inches deep. The pumps are now connected with the engine as before. Fuel, well ignited, is now placed in the fuel feeder filling two thirds of the space between the valves, which is dropped into the furnace in the manner already described. The valve admitting the motive power to the engine is now opened. The introduction of the burning fuel into the furnace, by heating and expanding the air therein and augmenting its pressure, sets the engine in motion. One or two revolutions of the machinery causes the highly heated air from the furnace to enter the generator, which almost instantly causes an evolution of steam, by heating the water contained therein. All the plates opposite the sprinklingv -be eiected, with an equal heating surface,

in an ordinary steam boiler, forming altogether an immense steam producing capac ity in a very small space. A very small amount of fuel will maintain the power of the engine.

The method described, for putting the engine in motion wil-l serve for small and moderate sized engines. Large engines will require a small hand pump to supply chamber C, with condensed air preparatory to setting the engine in motion. A reservoir communicating with pipe P, may also be an advantage to large engines, on which the hand pump in the last case should be located, so that said reservoir may be supplied with condensed air, with either the engine, or hand pump. When the engine is not in motion, the fuel ceases to burn except in a small degree. F or engines 'that are often required to stop, there will be required a small engine and air pump, (termed a doctor,) to supply the re with air sufficient to maintain a slow combustion while the larger engine is at rest.

rlhe ash pan R, and furnace B, are removable; the head of chamber C, being taken off for that purpose; which should be done once a day to remove the ashes accumulated in them.

The constant agitation of the water in the generator prevents mud, lime, and other impurities from adhering to its interior, by being kept in solution in "the water, which latter should be expelled once a day through mud pipe T, and its place supplied by fresh water. Vhen the Vengine stops for any considerable length of time in'cold weather, the water should be expelled, which being small in quantity may be supplied fresh in one or two minutes, thus obviating the difliculties incident to freezing.

The escape steam, &c., from the engine in the furnacewhile partly drawn out; but the condensed air from the reservoir must be admitted to the fire immediately on closing the head of chamber C; otherwise the want of air will extinguish the newly kindled fire.

Sometimes the pressure in the steam generator, may be for a moment, greater than in the furnace; and when this is the case, the valve on the end of pipe H, prevents the water from being forced out of the generator into space F.

It may be observed, that no part of my apparatus, subject to pressure, is liable to be overheated. The condensed air from the air pump, previous to entering the furnace, circulates on all sides of the latter, in the air space between the furnace chamber A, and the outer chamber C, by which the latter is kept cool. The hot air from the furnace, after entering the generator, loses a large portion of its heat by mixing with the water, by which said generator is prevented from being overheated.

With good material used in the construction of my invention, there can be no danger of an explosion. The metal used should be capable of sustaining a pressure consid- `erably above that assigned as the highest limit of pressure used in running the venv gine. When explosions occur from neglect of this precaution, there can be but little damage as the result, in consequence ofthe Asmall space occupied by the motive power.

Any kind of engine may be used lwith my invention, that can be used with steam or hot air separately. The weight and size of my invention need not be more than one fifteenth the size of steam boilers, (with their adjunts,) commonly in use, of the same power.

The supply of air to the furnace, and the admission of the water to the generator, being regulated by automatic devices, render the working of my invention free from nearly all difficulties caused by negligent attendants. The small amount of fuel consumed, renders it necessary for but one man to supply fuel to the furnace, `even for large engines.

I do not claim the precise fo'rm and arrangement of the par-ts composing my invention; as said form and arrangement may be varied, and-yet retain the essential principles embodied in them. Nor do I claim the form and arrangement of the air pump, which latter is well known.

I claiml. The arrangement of the devices as set forth by which soot or ashes is prevented from entering thel generator; which devices also return a portionof the hot air and gases to the furnace to be reheated.

2. The arrangement of the plunger N,

and the devises en'neeted with it, by which .'mttingfthe escape of the cndensed air cons'ad plungerl acts asa 'safety valve,- pressure tained in the air space surrounding the furindcator, and regulator of the air passages nace, substantially as set forth. for limiting the amount of motive power Y DARIUS MUSSELMAN. 5 produced, substantially as set forth. Witnesses:

3. The arrangement of the feeder for in- H. L. MAUR, trodu'cing fuel into the furnace Without per- W. T. RIGGS. 

